Abstract: A method and apparatus for determining a small number of parameters that spectrally characterize colorants by a small number of parameters and for using such colorant parameters to accurately predict the spectral reflection or transmission characteristics of such colorants when deposited on top of one another, either on an opaque, transparent or semitransparent carrier of a particular type, each colorant deposited with a certain coverage percentage, for example, dot percentage in the case of offset printing, the colorant parameters of any colorant being substantially independent of the color of the substrate and including dependency on the colorants deposited before and after. The method involves making measurements of sets prints of varying coverage percentages of a colorant on a number of backgrounds, and solving the resulting set of equations for the colorant. Colorants that are defined by a recipe of basic colorants can be characterized from measurements on prints of the basic colorants.